Stuffing-box.



. UNITED STATES PATENT OFFIOE.

JULIUs H. O. BUNGE, oFv BUFFALO, NEW YORK.

STUFFING-BOX.

Specication of Letters Patent.

Patented May 7, 1907.

Original application iled February 14,1906, Serial No. 300,972. Divided and this application filed June 14, 1906. Serial No. 321,591.

To all whom t may concern,.-

Be it known that I, JULIUS H. O. B UNGE, a subject of the Queen of the Netherlands, residingr at Buffalo, in the county of Erie and State of New York, have invented a new and useful Improvement in Stuffing 'Boxes, of which the following is a s peci cation, this a plication being a division of my ap lication filed February v14, 1906, Seria No. 300,972.

This invention relates to that class of studing boxes for rotary shafts which are packed by a body of fluid contained between a stationary casing and a rotary member arranged therein and mounted on the shaft, the casing and the rotary member being provided with intermeshing annular projections which are se arated by a sinuous or zig-zag passage wiich is filled with said fluid. Heretofore these intermeshing annular projections have been arranged radially and side by side so that the sinuous or zig-zag passage formed between these projections extended along the shaft, while the individual legs of this passage were arranged radially and extended alternately away from the shaft and toward thc same. The object of this invention is to produce a more compact and more eflicient packing or stu'fling box of this character.

In the accompanying drawings: Figure 1 is a sectional elevation of the exhaust end of a steam turbine provided with my improved stuffing box. Fig. 2 is a longitudinal section of the box, on an enlarged scale. Fig. 3

is a front elevation of the box with the gland removed. Fig. 4 is a front elevation of the box.

Like letters of reference refer to like parts in the several figures.

A represents the rotary shaft to which the stuffing box is applied and which, in the machine shown inthe drawings, is the shaft of. a steam turbine but which may be the shaft of any other machine in which leakage along theshaft is to be prevented.

B represents the casing of the turbine, b the bucket wheels, andC one of the bearings.

The stufling box comprises a box or casing D which is secured to the casing B of the turbinel or other machine, a collar E which is secured tothe shaft to rotate therewith within the box D, a bottom ring F which is arranged l at the inner end of the box D, and a glan or cover G which is secured. to the outer end thereof. This collar is provided at both ends with concentric annular projections c which extend axially into spaces'between similar annular projections f and g formed, respectively, on the outer side of the bottom ring F and the inner side of the gland G. These annular projections intermesh or fit between each other with a slight clearance, suflicient to prevent contact, and this clearance forms a zig-zag or sinuous passage between each end of the rotary collar and the adjacent nonrotary member of the stuffing box.l This clearance is preferably somewhat greater lengthwise of the shaft than radially and the annular projections taper preferably from the base toward the edge'.

Steam or .some other fluid under pressure is supplied to the sinuous passages for the purpose of keeping the same filled with a fluid which is under suflicient pressure to prevent leakage along the shaft. In the case of a steam turbine steam is most conveniently used as the pressure fiuid and this steam is supplied to the sinuous passages of the box by a port h formed in the box and a supply pipe i Y connected therewith. The water of condensation is discharged from the sinuous passages by a port c formed in the box and a waste pipe l, which may lead to a trap of any suitab e construction.

The steam or other Huid under pressure fills the sinuous passages between the rotary collar and the non-rotaryparts of the box but is driven away from the shaft by the centrifugal force which is created by the rotation of the collar and its annular projections This centrifugal action and the friction which the steam or other pressure Huid encounters in the narrow sinuous passages result in a practical equilibrium of pressure around the shaft, whereby leakage of steam along the shaft is preventedfrom the inside of the turbine casing at the front or high pressure end of the casing, or of outside air to the inside of the casing at the exhaust or vacuum end thereof.

Each zig-zag passage comprises several legs which are arranged concentric'all each outer leg farther from the shaft than t e next inner one and each trending lengthwise of the shaft with a certain amount of Obliquity. Theintermeshing rings on the stationary casing and the rotary member are tapering in cross section and form adjacent to the edge or apex of each ring an enlarged chamber or pocket which accommodates more of the sealing fluid' than the friction in the narrow IIO spaces between the sides of the rings will allow to pass. The 'fluid expands in these chambers and the pressure of the fluid in successive legs of the passage is thereby greatly reduced and the iiow corres ondingly rej tarded. This action is cumu ative to that produced by the friction of the fluid against the confining walls.

The concentric arrangement of the individual legs ofthe zig-zag passage reduces the length of the packing space to that occupied by one of the legs, and the len thwise trend of the friction surfacescauses t e fluid to be massed in each leg by centrifugal force against one of these surfaces, whereby the frictional resistance'to the movement of the Huid is greatly increased.

I claim as In invention:

1. In a st box, the combination of a stationary and a rotary member, each provided with concentric rings which project lengthwise with reference to the axis of the rotary member, the rings of the two members v intermeshing and being separated by a zigzag passage composed of legs which are arranged concentrically, each outer leg further from said axis than the next inneraleg, substantially as set forth.

2. In a stufling box, the combination of va stationary member and a rotary member, each rovided with concentric rings trending lengt 1-Wise of the axis of the rotary member,

the rings of the two members intermeshing and being separated by a lzig-zag passage having enlarged chambers adjacent to the free ends of the rings, substantiallyas set forth.

8. In a stuffing box, the combination of a stationary member and a rotary member, each provided with concentric, tapering rings, the rings of the two members intermeshing and bein separated by a zig-zag passage having enIarged chambers adjacent to the free ends of the rings, substantially as set forth. l Witness my hand this 6th day of May, 1906. v

JULIU-s H. o. BUNGE.

Witnesses:

C. W. PARKER, C. B. HoRNBEcK. 

